This invention relates to methods for installation and repair of synthetic turf fields and areas. In another aspect, this invention relates to improved seams and/or inlays and methods for forming the same whereby a fastener element is employed to create a reinforced seam and/or inlay. In yet another aspect, this invention relates to a reinforced seam and/or inlay and method for forming the same, which is exceptionally strong, wear-resistant in indoor and outdoor installations, safe and cost efficient.
In recent years, synthetic turf materials have been widely used to cover athletic fields, parade grounds, playgrounds, highway medians, airport safety areas, runways and taxiways, areas surrounding swimming pools, patios, and the like. Such synthetic turf materials normally simulate a well manicured, natural grass surface in that the synthetic turf material is made up of a multitude of upstanding ribbon-like fibers that are secured to a base or a substrate. Such durable surfaces are now widely used for the surfaces of athletic playing fields and the like, wherein the synthetic turf is exposed to grinding, abrasive, and twisting forces, caused by the shoes of athletes, animals, and the like, as they walk or run across the surface of the synthetic turf.
The installation of synthetic turf material is some way resembles the installation of carpet material in that the synthetic turf material is unrolled, cut to the desired sizes, and the adjacent pieces of synthetic turf material are brought together by some manner and means.
Many different techniques have been utilized for the installation of synthetic turf materials.
One technique that has been utilized for the installation and repair of synthetic turf materials for seam or inlays utilizes a heat sealing technique and an adhesive, volatile solvent or heat activated adhesive material to seam. This is done by placing a piece of turf to be joined or attached on top of a shaven/trimmed area or turf. The adhesive, volatile solvent or heat activated adhesive material is applied to the shaven area and the piece to be attached is placed on top of the adhesive, volatile, solvent or heat activated adhesive material. Thereafter, by the application of pressure to compress the lower portion of the abutted edges into the adhesive material on the surface of the tape material, some fusion or adhesion will take place to thereby form a bond between the abutted edges of the synthetic turf material and the surface of the tape material. Once the adhesive, volatile solvent or heat activated materials are cured and dried, it improves the structural properties of joined/seamed or attached pieces of synthetic turf.
Particularly if the synthetic turf is to be laid on a playing field for a certain type of sport, for example, on a tennis court, a football field or the like, lasting playing field marking lines are required in the turf material. It is not uncommon to use separately manufactured material strips, which are usually inserted into a gap of corresponding width cut into the turf material after it has been laid for the playing field marking lines. By application of various types of glue, material and adhesive material, wherein some type of a reinforcement cloth type material/tape is positioned beneath the abutted edges of the synthetic turf material to be seamed, the joining strip is coated with an adhesive and serves to bond the underside of the turf material with the underside of the material strip acting as playing field marking lines. Use of such a joining strip in the form of an adhesive strip can be problematic as correction of the material parts to be aligned with one another is extremely difficult once an adhesive connection has been established. Also, handling of the adhesive strip is bothersome due to the adhesive spontaneously adhering to everything with which it comes into contact, resulting in the hands and appliances of the workmen laying the ground covering being soiled after only a short time by the adhesive residues which, to say the least, severely impedes precise workmanship.
Another problem with this process is that it is often necessary to place a weight of some sort on the seamed/joined areas to keep the glue/adhesive, volatile solvent or heat activated adhesive material in direct contact with both the turf backing and cloth type material/tape or shaven area on top of a piece of turf. Another process for maintaining contact between the adhesive material and the turf backing and the seaming/cloth tape material involves the use of various type of rollers where the roller is moved across the seamed/joined area applying pressure to the top piece of synthetic turf and to press it downward into the adhesive, volatile solvent or heat activated material on top of cloth type material/tape or shaven area of another piece of turf. Pressure is constantly or repeatedly applied until the adhesive, volatile solvent or heat activated material starts to cure, firm up and or dry to the stage of getting very tacky, sticky, and gooey to the degree that it can hold the two adjacent surfaces together itself. When using a weight it usually needs to remain in place for 8-24 hours and the workmen usually leave and return the following day to remove the weight. This is another cost associated with the current industry process.
Repeating this process for all of the hash marks, non-tufted lines, numbers, logos, and letters on synthetic sports fields is a major part of the installation process and contributes significantly to the cost of installation. Those projects where this process is rushed and not done properly create a majority of the repair work needed down the road once the field is played on due to the pressure and stress of athletes and kids playing on the surface supported only by the contact between the adhesive, volatile solvent or heat activated material and cloth type material/tape that was used during the installation process. A significant problem with creating strong seams and inlays is the inconsistent surface of tufts that extend out through the backing of the turf. Historically the industry has not been able to develop a coating that would adhere to the tufts without flaking off. The tufts act like stilts preventing the backing from lying uniformly down in the adhesive and those tufts are often the source of most of strength of the seam. The constant process of rolling and weighting the seams and inlays is to drive the backing of the turf down into the adhesive to create additional contact points exceeding the tufts.
Other techniques have been proposed wherein an attachment means is additionally employed for seams and inlays in both the synthetic turf industry and carpet installation industry such as hook and loop fastener elements (U.S. Pat. No. 4,755,401 rib and groove fastener profile (U.S. Pat. No. 4,581,269) tacks (U.S. Pat. No. 5,693,171) and staples. However these attachment means are inadequate and often unsafe for synthetic turf playing fields.
It is, therefore, apparent that there is a need for improved seams and inlays and a method for forming the seams between the abutted edges of synthetic turf material and for forming inlays. It is also apparent that there is a need for improved seams and inlays and method for installing seams and inlays that is quick and can be easily done under field conditions and can maintain its strength over long periods of use and exposure to the elements.